docs: flip site_url + AGENTS reference to apex openarmature.ai (#34)

The docs site now lives at https://openarmature.ai/ (apex) rather than
the originally-scoped docs.openarmature.ai subdomain — for the Phase A
launch we don't have a separate landing site, so the top level is the
natural home. mkdocs.yml's site_url is the canonical-link / sitemap /
OG-meta source, so it has to match where visitors actually land.

AGENTS.md's docs section updated to reference the new URL.

Author: chris-colinsky

AGENTS.md

@@ -105,7 +105,7 @@ Commit subjects follow the 50/72 rule — subject ≤ 50 chars (hard cap
 ## Docs
 
 User-facing docs live in `docs/` and build via MkDocs Material; the
-deployed site is at `docs.openarmature.ai`. CI build + deploy is in
+deployed site is at `openarmature.ai`. CI build + deploy is in
 `.github/workflows/docs.yml`. Local preview: `uv run mkdocs serve`.
 
 ## Engine design notes that are easy to miss

mkdocs.yml

@@ -1,5 +1,5 @@
 site_name: OpenArmature
-site_url: https://docs.openarmature.ai/
+site_url: https://openarmature.ai/
 site_description: Workflow framework for LLM pipelines and tool-calling agents
 copyright: "©OpenArmature 2026 to present"
 repo_url: https://github.com/LunarCommand/openarmature-python